Heat-dissipating device with dissipating fins drivable to move within and ambient fluid

ABSTRACT

A heat-dissipating device includes a hollow housing adapted to contact a heat source and for receiving a heat-conducting fluid therein, a heat-conducting member contacting the heat-conducting fluid, and a heat-dissipating fin unit driven to move within an ambient fluid so as to dissipate heat from the fin unit to the ambient fluid.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority of Taiwanese Application No.91115210, filed on Jul. 9, 2002.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a heat-dissipating device, and moreparticularly to a heat-dissipating device that includes heat-dissipatingfins which can be driven to move within an ambient fluid so as topromote the heat dissipation efficiency of the device.

[0004] 2. Description of the Related Art

[0005] A conventional heat-dissipating device normally includes aheat-conducting member contacting a heat source, a plurality ofheat-dissipating fins fixed on the heat-conducting member so as todissipate heat from the heat-conducting member to an ambient fluid, suchas air, and a fan for blowing air toward the fins. According to the windchill effect, when the speed of air current flowing from the fan ontothe fins increases by 100 meters per second, the surface temperature ofthe fins will reduce by only about 1° C. in view of a limited relativespeed between air and the fins. As such, when the heat source has acomparatively high temperature, there is a need for a fan of a largersize to create a faster air current, thereby increasing the volume andmanufacturing costs of the conventional heat dissipating device.

SUMMARY OF THE INVENTION

[0006] The object of this invention is to provide a heat-dissipatingdevice that includes a plurality of heat-dissipating fins, which can bedriven to move within an ambient fluid so as to increase significantlythe relative speed between the ambient fluid and the fins, therebypromoting the heat dissipation efficiency of the device.

[0007] According to this invention, a heat-dissipating device includes ahollow housing adapted to contact a heat source and for receiving aheat-conducting fluid therein, a heat-conducting member contacting theheat-conducting fluid, and a heat-dissipating fin unit driven to movewithin an ambient fluid, such as air, so as to dissipate heat from thefin unit to the ambient fluid. As such, a relatively high relative speedbetween the ambient fluid and the heat-dissipating fin unit can beobtained so as to enhance the wind chill effect, thereby increasing theheat dissipation efficiency significantly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features and advantages of this invention willbecome apparent in the following detailed description of the preferredembodiments of this invention, with reference to the accompanyingdrawings, in which:

[0009]FIG. 1 is a schematic sectional view of the first preferredembodiment of a heat-dissipating device according to this invention;

[0010]FIG. 2 is a schematic sectional view of the second preferredembodiment of a heat-dissipating device according to this invention;

[0011]FIG. 3 is a schematic top view of two heat-dissipating fins of thesecond preferred embodiment;

[0012]FIG. 4 is a schematic sectional view of the third preferredembodiment of a heat-dissipating device according to this invention; and

[0013]FIG. 5 is a schematic view of the fourth preferred embodiment of aheat-dissipating device according to this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Before the present invention is described in greater detail inconnection with the preferred embodiments, it should be noted thatsimilar elements and structures are designated by like referencenumerals throughout the entire disclosure.

[0015] Referring to FIG. 1, the first preferred embodiment of aheat-dissipating device according to this invention is shown to includea heat-absorbing mechanism 1 and a heat-dissipating mechanism 2.

[0016] The heat-absorbing mechanism 1 includes a hollow primary housing11 that is made of a heat-conducting material and that is adapted tocontact a first heat source 3, such as a CPU chip, so as to permit heattransfer from the first heat source 3 to the primary housing 11, and aheat-conducting fluid 12 that is received within the primary housing 11so as to permit heat transfer from the primary housing 11 to theheat-conducting fluid 12. The primary housing 11 has a contacting wall111 that contacts the first heat source 3, and a mounting wall 112 thatis parallel to the contacting wall 111 and that is formed with acircular hole 112 therethrough. The heat-conducting fluid 12 may be gas,liquid, or a coolant.

[0017] The heat-dissipating mechanism 2 includes a driving unit 21, aheat-conducting member 22, a bearing unit 23, a connector 24, and aheat-dissipating fin unit consisting of two heat-dissipating fins 25.The driving unit 21 is configured as an electrical motor. Theheat-conducting member 22 is configured as a motor shaft that is rotatedby the driving unit 21 and that has a first end 221 and a second end222. The first end 221 is journalled on the primary housing 11 by meansof the bearing unit 23, and extends into the primary housing 11 throughthe circular hole 113 in the mounting wall 112 of the primary housing11. The second end 222 is connected to the driving unit 21 by means ofthe connector 24. The fins 25 are connected fixedly to and extendradially and outwardly from the second end 222 of the heat-conductingmember 22. An outward flange 224 is formed on the first end 221 of theheat-conducting member 22, is disposed in the primary housing 11 so asto contact the heat-conducting fluid 12, thereby permitting heattransfer from the heat-conducting fluid 12 to the heat-conducting member22, and has a diameter that is larger than that of the circular hole 113in the primary housing 11 so as to prevent removal of theheat-conducting member 22 from the primary housing 11. The fins 25 areexposed within an ambient fluid, i.e. air. As such, when the drivingunit 21 runs, the fins 25 rotate about the heat-conducting member 22 ata relatively high speed relative to the ambient fluid so as to enhancethe wind chill effect, thereby permitting rapid heat transfer from thefins 25 to the ambient fluid. Alternatively, the fins 25 can be drivento perform reciprocating linear movement, swinging movement, or anyother similar motion relative to the first heat source 3.

[0018]FIGS. 2 and 3 show the second preferred embodiment of aheat-dissipating device according to this invention, which is similar tothe first preferred embodiment in construction. Unlike the firstpreferred embodiment, the heat-conducting member 22 is hollow, and isformed with a central bore 220, and the heat-dissipating mechanism 2further includes two tubes 26 that are connected respectively andfixedly to the fins 25. The central bore 220 has an open end 221 influid communication with an interior chamber 110 in the primary housing11, and a closed end 222 proximate to the driving unit 21. Each of thetubes 26 extends along a spiral path on the corresponding fin 25, andhas a closed outer end 261, and an open inner end 262 in fluidcommunication with the central bore 220 in the heat-conducting member22.

[0019]FIG. 4 shows the third preferred embodiment of a heat-dissipatingdevice according to this invention, which is similar to the secondpreferred embodiment in construction. Unlike the second preferredembodiment, no tubes 26 are provided, and each of the fins 25 is hollow,and is formed with an interior space 250 that has a closed radial outerend 251 and an open radial inner end 252 that is in fluid communicationwith the central bore 220 in the heat-conducting member 22.

[0020]FIG. 5 shows the fourth preferred embodiment of a heat-dissipatingdevice according to this invention, which is similar to the thirdpreferred embodiment in construction. Unlike the third preferredembodiment, the heat-absorbing mechanism 1 further includes a hollowsecondary housing 13 that is adapted to contact a second heat source 3′so as to permit heat transfer from the second heat source 3′ to thesecondary housing 13, and a conduit 14 that is connected removably toand that is in fluid communication with the primary and secondaryhousings 11, 13. The first and second heat sources 3, 3′ constitute aheat source unit.

[0021] With this invention thus explained, it is apparent that numerousmodifications and variations can be made without departing from thescope and spirit of this invention. It is therefore intended that thisinvention be limited only as indicated by the appended claims.

I claim:
 1. A heat-dissipating device for dissipating heat from a heatsource unit to an ambient fluid, said heat-dissipating devicecomprising: a heat-absorbing mechanism including a hollow primaryhousing that is made of a heat-conducting material and that is adaptedto contact the heat source unit so as to permit heat transfer from theheat source unit to said primary housing, and a heat-conducting fluidthat is received within said primary housing so as to permit heattransfer from said primary housing to said heat-conducting fluid; and aheat-dissipating mechanism including a heat-conducting member thatcontacts said heat-conducting fluid so as to permit heat transfer fromsaid heat-conducting fluid to said heat-conducting member, aheat-dissipating fin unit that is mounted to said heat-conducting memberso as to permit heat transfer from said heat-conducting member to saidheat-dissipating fin unit and that is adapted to be exposed within theambient fluid so as to permit heat transfer from said dissipating finunit to the ambient fluid, and a driving unit connected to saidheat-dissipating fin unit so as to drive said heat-dissipating fin unitto move within the ambient fluid.
 2. The heat-dissipating device asclaimed in claim 1, wherein said driving unit is configured as anelectrical motor, said conducting member being configured as a motorshaft that is rotated by said electrical motor, said heat-dissipatingfin unit including a plurality of fins that are connected fixedly to andthat extend radially and outwardly from said motor shaft so that saidelectrical motor can rotate said fins about said motor shaft.
 3. Theheat-dissipating device as claimed in claim 2, wherein said primaryhousing has an interior chamber for receiving said heat-conducting fluidtherein, said motor shaft being hollow and being formed with a centralbore that has a closed end proximate to said electrical motor, and anopen end in fluid communication with said interior chamber in saidprimary housing.
 4. The heat-dissipating device as claimed in claim 3,wherein said heat-dissipating mechanism further includes a plurality oftubes that are connected respectively and fixedly to said fins, each ofsaid tubes having a closed outer end, and an open inner end in fluidcommunication with said central bore in said motor shaft.
 5. Theheat-dissipating device as claimed in claim 4, wherein each of saidtubes extends along a spiral path on a respective one of said fins. 6.The heat-dissipating device as claimed in claim 3, wherein each of saidfins is hollow, and is formed with an interior space that has a closedradial outer end and an open radial inner end, which is in fluidcommunication with said central bore in said motor shaft.
 7. Theheat-dissipating device as claimed in claim 6, wherein saidheat-absorbing mechanism further includes a hollow secondary housingthat is adapted to contact the heat source unit so as to permit heattransfer from the heat source unit to said secondary housing, and aconduit that is connected removably to and that is in fluidcommunication with said primary and secondary housings.
 8. Theheat-dissipating device as claimed in claim 2, wherein saidheat-dissipating mechanism further includes a bearing unit, said motorshaft being journalled on said primary housing by means of said bearingunit, said primary housing having a contacting wall that is adapted tocontact the heat source unit, and a mounting wall that is parallel tosaid contacting wall and that is formed with a circular holetherethrough, said motor shaft extending into said primary housingthrough said circular hole and being formed with an outward flange thatis disposed in said primary housing and that has a diameter which islarger than that of said circular hole in said primary housing so as toprevent removal of said motor shaft from said primary housing.